Operation apparatus for change speed machine



P 2, 1969 TAKANORI ONDA 3,464,280

OPERATION APPARATUS FOR CHANGE SPEED MACHINE Filed Aug. 50, 1967 4 Sheets-Sheet 1 p 2, 1969 TAKANORI ONDA 3,464,280

OPERATION APPARATUS FOR CHANGE SPEED MACHINE Filed Aug. 30, 196'? 4 SheetsSheet 2 p 2, 1969 TAKANORI ONDA 3,464,280

OPERATION APPARATUS FOR CHANGE SPEED MACHINE Filed Aug. 30. 1967 4 Sheets-Sheet 3 P 1969 TAKANORI ONDA 3,464,280

OPERATION APPARATUS FOR CHANGE SPEED MACHINE Filed Aug. 30. 1967 4 Sheets-Sheet 4 United States Patent i US. Cl. 74-142 7 Claims ABSTRACT OF THE DISCLOSURE A speed change machine is provided in which a speed change drum having pins thereon is angularly movable between first and second speed positions by engagement of the pins with claws on an arm movable in opposite directions. The arm and drum have respective projections which are engaged to positively lock the drum in a neutral angular position as the drum is moved from one of the speed positions to the other by the movement of the arm in one direction thereof, the drum having a cam for angularly displacing the arm as it is retracted in the opposite direction when the drum is locked so that subsequent movement of the arm in the original direction can be effected without 'engagementof the projections whereby the drum can be rotated tothe other speed position.

BRIEF SUMMARY OF THE INYENTION The present invention relates to improvements in the operation apparatus of speed change machines.

There has been hitherto known a change speed machine of the type in which several engaging pins are annularly arranged on the side surface of a change speed drum and two opposite operation claws movable with a change speed pedal are engaged with said engaging pins, so that the change speed drum may be rotated and stopped at sevskillfully regulate a tral position regardless of the operators skill in the pedal operation. It

A characteristic feature of the invention is that, when an operation claw is engaged with an engaging pin of a change speed drum situated-at the second speed position and the drum is in the neutral position, further advance of the operation claw is positively restrained by the change speed drum, but if, subsequently, the operation claw, after being retracted once, is advanced again, the above restraint is released and thereby the change speed drum is permitted to rotate from the neutral position to the first speed position. A second feature of the present invention is that a mechanism for the above restraint is composed of an engaging projection on the change speed drum and an engaging projection on a change speed arm connected to the operation claw. The release for the restraint mechanism is effected by a cam on the drum which displaces the arm during its retracting movement so that the projection will not be engaged upon subsequent advance of the arm.

drum is advanced toward the first speed position until the r Patented Sept. 2, 1969 ice BRIEF DESCRIPTION OF THE DRAWING FIGURES 1 to 4 are side views of the apparatus of the present invention in different operating conditions;

FIGURE 5 is a side view of a cam plate viewed in the direction of arrow X in FIG. 2;

FIGURE 6 is a sectional view taken along the line VI-VI in FIG. 1;

FIGURE 7 is a sectional view taken along the line VII-VII in FIG. 2; and

FIGURES 8 and 9 are sectional views similar to the above but showing the operating conditions following the operating condition in FIG. 7.

, DETAILED DESCRIPTION Referring to FIGS. 1 to 6, numeral 1 denotes a change speed drum, which is rotatably supported by a body F, for operating a speed change mechanism of a running vehicle. A swing arm 2 is secured at its lower end to a pedal shaft 3, and the arm 2 is normally held in a neutral position as shown in FIG. 1 by the arms 4 of a holding spring which engage a stationary pin 5 therebetween. The arm 2 can swing to the right and to the left by operating a pedal (not shown) of a pedal arm 6. The swing arm 2 is rotatably connected via axle 7 to the rear end portion of a change speed arm 8, which is provided with two operation claws 9 and 10 facing one another. The change speed drum 1 has a deep annular groove 11 at one end thereof, within which are several unidiameter engaging pins 12 and a single engaging pin 13 with a head 13A defining a step. The pins are arranged at regular intervals in an annular array about the axis of the change speed drum 1. The top end portion of the change speed arm 8 is received in the annular groove 11 and two of the engaging pins are positioned between the operation claws 9 and 10. A spring 14 acts on arm 8 to urge the top end thereof inwardly in annular groove 11. The change speed drum 1 has a cam plate 15 secured thereto by a screw 16 at the outside of the annular groove 11. In the periphery of the cam plate is a first speed concavity 17, a second speed concavity 18 and any desired number of consecutive concavities, for example, third and fourth speed concavities 19 and 20 at regular intervals. Additionally, a neutral position concavity 21 is provided between the first and second speed concavities 17 and 18. Numeral 22 denotes a swingable stopper having a roller 23 thereon for engaging the concavities to stop the change speed drum 1 at each change speed position and the neutral position; the stopper 22 is urged by a suitable spring (not shown) towards the cam plate 15. The above construction is conventional except for the step engaging pin 13 and for the slightly inclined arrangement of the spring 14 as shown in FIG. 6 so that the top end of the change speed arm 8 is urged against the outside wall surface 11A of annular groove 11.

Additionally, in the present invention, there is provided on the inner surface of the cam plate 15 in the neighborhood of the step engaging pin 13 (between the second speed concavity 18 and the third speed concavity 19) an engaging projection 24 having almost the same height as theoutside wall surface 11A of the annular groove 11, for engaging a projection 26 on the arm 8 as will be explained more fully hereinafter. I

There is also provided on the cam plate 15 adjacent to the projection 24 a projection cam 25 for slightly shifting the change speed arm 8 inwardly. The engaging projection 26 is situated at a position near the axle 7 of the change speed arm 8 and projects laterally as shown for example in FIG. 6.

The operation of the apparatus is as follows:

When the roller 23 is in engagement in the second speed concavity 18 and the change speed drum 1 is situated at the second speed position as shown in FIGS.

1 and 6, the step pin 13 and an adjacent engaging pin 12 are engaged between the operation claws 9 and 10. If, now, for the purpose of rotating the change speed drum 1 to the neutral position, the change speed arm 8 with the engaging projection 26 is advanced (to the right in FIG. 1) by means of the pedal arm 6, the engaging claw 9 engages the head 13A of the pin 13 and rotates the change speed drum 1 toward the first speed position. However, the engaging projection edge 24 and the cam 25 are also rotated in accordance with this rotation, and the engaging projection edge 24 enters into the path of advancement of the engaging projection 26 as shown in FIG. 2 when the neutral position concavity 21 is engaged with the roller 23 and the change speed drum 1 is stopped at the neutral position. Accordingly, the engaging projection 26 is in abutment with and is stopped by the engaging projection edge 24 as shown in FIG. 7 even if it is intended to further advance the change speed arm 8, so that the change speed drum 1 is positively stopped at the neutral position and can never be overrun toward the first speed position. On this occasion, the cam 25 enters the return path of the operation claw 9, as shown in FIG. 2 so that if the change speed arm 8 is then retracted by the operation of the pedal arm 6, the operation claw 9 runs on the cam 25 as shown in FIGS. 3 and 8 so that the top end portion of the change speed arm 8 is displaced against the action of spring 14, whereby the top end portion of arm 8 is slipped from the periphery of the head 13A of the pin 13 and is brought past the step onto the smaller diameter portion of the engaging pin 13 in abutment with the inner surface of the head 13A. Thereby the change speed arm 8 is inclined inwards slightly as shown in FIG. 8. If, as a result, the change speed arm 8 is then advanced, the advance direction of the engaging projection 26 is moved out of the path of the projection 24 as shown in FIG. 9, so that by pedalling the pedal arm 6 the engaging claw 9 is engaged with the smaller diameter portion of the pin 13 to rotate the change speed drum 1 to the first speed position as shown in FIGS. 4 and 9. If, after the change speed drum 1 has been rotated to the second speed position by pedalling in reverse direction of the pedal arm 6, and said arm 6 is released to return to its neutral position, the operation claw 10 is engaged with the front side engaging pin 12 so that the change speed arm 8 is pushed outwards in relation to the change speed drum 1, whereby the change speed arm 8 is brought into a position in which it is in engagement with the periphery of the head 13A.

Thus, the apparatus of the present invention is so op-. erated that when the change speed drum has taken the neutral position by being rotated from the second speed position toward the first speed position, further advance movement of the operation arm, namely, the operation claw for rotating the change speed drum is positively prevented by the change speed drum, so that the change speed drum is positively stopped at the neutral position regardless of an operators skill in the pedalling operation of the change speed pedal. Additionally, according to this invention, the provision of the engaging projection and the cam on the change speed drum as well as the engaging projection on the change arm renders the construction simple and the operation reliable.

In effect the projections 24 and 26 serve as a blocking means to form a detent for the drum when it assumes an angular position in which the roller is engaged in the neutral concavity as the drum moves from the second speed position to the first position, whereas the cam 25 serves as a release means for moving the arm 8 through an angular displacement as the arm is retracted so that subsequent operation of the arm 8 to move the drum to the first speed position is permitted since the projection 26 will now be out of the path of projection 24.

What is claimed is:

I. In a speed change machine wherein a speed change v drum having engaging pins therein is angularly movable between first and second speed positions by the engagement of said pins with claws on an arm movable in opposite directions, an improvement comprising blocking means on the arm and drum for being engaged to hold the drum in an angular position corresponding to a neutral position as the arm moves in one direction to move the drum from one of the speed positions towards the other, and release means On the drum for displacing the arm as the arm is retracted in the opposite direction such that a successive operation of the arm in said one direction can be effected without engagement of the blocking means so that the drum can be rotated to said other speed position, said blocking means comprising a projection on the arm and a projection on the drum, said projection on the arm moving into engagement with the projection on the drum to block further movement thereof when the drum is in said neutral position, said release means comprising a cam on said drum for engaging the arm as it is retracted to displace the arm such that as the arm is subsequently moved in said one direction the projection on the arm is out of the path of the projection on the drum, one of said pins including two portions of different diameter with a step therebetween, said arm being in contact with the larger diameter portion as the arm moves the drum from the second speed position to the first speed position, said cam acting on the arm to displace the same from the larger diameter portion to the smaller diameter portion thereby enabling pivotal movement of the arm about an axis remote from said one pin.

2. An improvement as claimed in claim 1 wherein said one pin has an axis with the portions of different diameter in axial extension therealong, the axis of said one pin being parallel to the axis of pivotal movement of the pin.

3. An improvement as claimed in claim 1 comprising a plate on said arm having concavities corresponding to the speed positions and the neutral positions, said cam and the projection on the drum being on said plate.

4. An improvement as claimed in claim 1 comprising spring means acting on said arm to urge the same to a limit angular position on the drum, said cam acting on the arm in opposition to the action of the spring means.

5. An improvement as claimed in claim 4 wherein said arm comprises a flat plate portion which includes the claws, said spring means being a spring acting on said arm at an angle with respect to said fiat plate portion to urge the same laterally against the drum.

6. An improvement as claimed in claim 3 wherein said projection on said plate is immediately adjacent one of said concavities.

7. An improvement as claimed in claim 1 wherein said drum has an annular groove in which said pins transversely extend, said arm being positioned in said groove and urged inwardly for contacting said pins, said arm being in contact only with the larger diameter portion of the said one pin when the drum is in the neutral position so that the action'of the cam on the arm causes the latter to slide along said one pin from the larger diameter portion thereof to the smaller diameter portion.

References Cited UNITED STATES PATENTS 715,975 12/1902 Carichotf 74--577 3,216,265 11/1965 ChriStOtT 74-442 3,358,519 12/1967 Christianson 74-l42 FRED C. MATTERN, 1a., Primary Examiner W. S. RATLIFFE, Jn., Assistant Examiner U.S. C1.X.R. 

